Smokeless furnace.



110 7875106. I PATENTED APR. 18, 1905. P. D. SHEPHERD.

SMOKELESS FURNACE.

APPLICATION FILED MAR. 12, 1903.

Patented April 18, 1905.

UNITED STATES ATENT UFFICE.

FRANK D. SHEPHERD, OF SALT LAKE CITY, UTAH.

SIVIOKELESS FURNACE.

SPECIFICATION forming part of Letters Patent NO. 787,406, dated April 18, 1905.

Application filed March 12, 1903. Serial No. 147,504.

To 111/ lr/mnt it may IOII/(FITIJ/J Be it known that l, FRANK l). Snnrnnun, of Salt Lake (ity, in the county of Salt Lake, and in the State of Utah, have invented a certain new and useful lmprovement in Smokeless Furnaces; and .1 do hereby declare that the following is a full, clear, and exact description thereof, reference being bad to the accompanying drawings, in which 4 Figure l is a vertical longitudinalsectional view of a boiler having a construction of furnace embodying my invention. Fig. 2 is a horizontal sectional view taken on the lineZZ of Fig. l. Fig. 3 is an end view of the construction illustrated in Fig. 1. Figs. land 5 are respectively vertical transverse sectional views taken on the linesl 4: and 5 5 of Fig. l.

lheobjectof myinvention has been to provide a furnace which, while especially adapted for use on steam-boilers, is capable of use for other purposes and which shall have the advantage of producing substantially perfect comlmstion, so that the generation of smoke is avoided; and to such ends my invention consists in the smokeless furnace hereinafter specilied and claimed.

in carrying my invention into practice, as illustrated in the drawings, I provide a boiler A, set within front, side, and rear walls B, U, and 1), respectively, the boiler, as shown, being supported in the front wall B and by angle-plates 1/. secured to the sides of the boiler. (irate-bars 1*] are supported upon the front wall B and upon a bridge-wall F at their rear ends. The front wall is preferably provided with the usual metal front, which is provided, preferably, with a pair of openings /1 above the grate-bars for the introduction of fuel, such openings beingclosed by the usual doors 0, and such wall is also provided with a pair of lower openings 7)", which are closed by a pair of doors 6, ti zsaid lower openings being for the removal of ashes.

My furnace is preferably fired by the introduction of fresh fuel on one side only of the grate at a time, since this mode of operation prevents the formation of as large an amount of smoke as would be formed by covering the whole tire with fresh fuel, and such tiring causes the gases upon one side of the furnace to be charged with an excess of carbon, while the gases upon the opposite side of the furnace contain an excess of highly-heated oxygen. In order to cause the thorough inter-mingling of the gases from the opposite sides of the furnace, so that an excess of carbon from the one side may be mixed with an excess of oxygen on the other side and complete combustion take place, I provide a wall (1?, extending from the floor to the boiler, which wall is provided with a central vertical passage-way r which thus divides the wall practically into two parts. The gases in passing through the passage-way 1/ are thoroughly intermingled, and the oxygen and carbon combine to produce perfect combustion. \Vhen the said passage alone is used for the passage of gases through the wall (l, l [ind that the portions of the boiler at the rear of the said wall and upon each side of the opening are apt to be less heated than the portion immediately to the rear of the said passage and in order to cause equal heat and equal expansion provide openings 9 in the two sections of the wall G, so that gases can pass through the said sections and reach the boiler at each side of the opening Although the gases which pass through the openings are apt to have an excess either of carbon or of oxygen, 1 find that such gases after passing through the said wall become thoroughly mixed with the gases which pass through the passage 1 so that perfect combustion results.

\Vherc the draft is sutlicient, I find the best results to be obtained by drawing in the air from beneath the grate; but if the draft obtained in this way is not sufficient l prefer to use means for-increasing the draft, and it is entirely immaterial to my improvements in the furnace how this increase of draft is obtained. l prefer to obtain it by means of an injector L of any desired construction. The injector is mounted, preferably, in a central position in the front wall B of the furnace, as illustrated in Fig. 3, so that air is thrown to each side of the furnace and is reflected by the side walls thereof toward the passage in the wall G, thus causing the currents formed by the injector to converge toward the passage g.

In the operation of my furnace the fuel is thrown upon one side of the upper surface of the grate, and this may be accomplished either by introducing fuel through one of two doors, as I have illustrated the furnace, or through a single central door. The fire causes smoke to rise from the freshly-applied fuel, and this smoke is driven or drawn toward the passage 9. At the same time air passes through the fire on the opposite side of the grate, and an excess of air is provided, so that the oxygen therein is not completely con-' sumed, as the volatile elements of the fuel through which it passes have previously been driven off. The gas thus having an excess of oxygen moves toward the passage before mentioned and there is mingled with the gas having an excess of carbon, and I have found in actual practice of my invention a high degree of perfection of combustion is obtained. At the same time a portion of smoky gases pass through the openings g, and a portion of the gases having an excess of oxygen pass through the corresponding openings in the opposite section of the wall, and the said gases after their passage through the said-wall are found to become throughly mixed with the gases which have passed through the opening g, so that substantially perfect combustion occurs. In this manner the under surface of the boiler at the rear of the wall having the passages is caused to be equally ex panded. If the draft is not sufliciently strong without the use of the injector or equivalent means, such injector is put into operation. In actual practice I have found most satisfactory results to be obtained by my furnace and substantially perfect combustion to result from its use.

It is to be understood that while I have chosen the application of my furnace to a steam-boiler for the purpose of illustration it is equally well adapted for other uses.

Having thus described my invention, what I claim is The combination of a boiler, having walls forming an inclosed space beneath the same, a bridge-wall in the forward portion of said space, a grate supported by said bridge-wall and the front of said inclosing walls, said front wall having doors on both sides of the center of said grate and above and below said grate, and a wall in the rear of said bridgewall, said last-mentioned wall extending from the floor to and fitting the lower surface of the boiler and being provided with a large central opening extending to the under surface of the boiler and being also provided with small apertures in the portions thereof on each side of the said opening and near the under surface of the boiler.

In testimony that I claim the foregoing I have hereunto set my hand.

FRANK D. SHEPHERD.

Witnesses:

C. M. CHANDLER, I. R. SHEETS. 

